Page 328 - ILAE_Lectures_2015

Chapter 33

Treatment of tonic-clonic status epilepticus

MATTHEW C. WALKER and SIMON D. SHORVON

Institute of Neurology, University College London, National Hospital for Neurology and
Neurosurgery, Queen Square, London
_________________________________________________________________________

Tonic-clonic status epilepticus can be defined as a condition in which prolonged or recurrent
tonic-clonic seizures persist for 30 minutes or more. Most tonic-clonic seizures last less than
two minutes; nevertheless many seizures that continue for less than 30 minutes self-terminate.
Treatment of the premonitory stages is likely to be more successful than treatment in the later
stages and so treatment should commence as soon it is apparent that the seizure is persisting
(a tonic-clonic seizure of more than five minutes’ duration) or there is a significant worsening
of a patient’s normal seizure pattern.

From indirect studies, the annual incidence of tonic-clonic status epilepticus has been
estimated to be approximately 1828 cases per 100,000 persons (900014,000 new cases
each year in the United Kingdom, or 45,00070,000 cases in the United States), and these
estimates have been largely confirmed in population-based studies. Tonic-clonic status
epilepticus is most frequent in children, the mentally handicapped, and in those with structural
cerebral pathology (especially in the frontal areas). In established epilepsy, status epilepticus
can be precipitated by drug withdrawal, intercurrent illness or metabolic disturbance, or the
progression of the underlying disease, and is commoner in symptomatic than in idiopathic
epilepsy. About 5% of all adult clinic patients with epilepsy will have at least one episode of
status epilepticus in the course of their epilepsy, and in children the proportion is higher
(1025%). Status epilepticus accounts for about 3.5% of admissions to neurological intensive
care, and 0.13% of all visits to a university hospital casualty department. The mortality of
status epilepticus is about 20%, most patients dying of the underlying condition rather than
the status epilepticus itself or its treatment. Permanent neurological and mental deterioration
may result from status epilepticus, particularly in young children; the risks of morbidity are
greatly increased the longer the duration of the status epilepticus episode.

General measures

For the new patient presenting as an emergency in status epilepticus, it is helpful to plan
therapy in a series of progressive phases (Table 1).

1st stage (010 minutes)

Oxygen and cardiorespiratory resuscitation. It is first essential to assess cardiorespiratory
function, to secure the airway, and to resuscitate where necessary. Oxygen should always be
administered, as hypoxia is often severe.